Crank-pin for steam-engines



(No Model.)

- A. K. EDDOWES.

- CRANK PIN FOR STEAM ENGINES. No. 286,404. Patented-0on9, 1883.

WITNESSES INVENTOR Q'!" M M UNITED STATES PATENT OFFICE.

ARCHIBALD K. EDDOVVES, OF PHILADELPHIA, PENNSYLVANIA.

CRANK-PIN FOR STEAM-ENGlNES.

SPECIFICATION forming part of Letters Patent No. 286,404, dated October 9, 1883.

Application filed J one .20, 1883.

To (LZZ whom it may concern:

Be it known that I, ARCHIBALD Knnnrox Ennowns, of the cityand county of Philadelphia, in the State of Pennsylvania, have invented certain new and useful Improvements in Crank-Pins for Steam and other Engines, of which improvements the following is a specification.

The object of my invention is to provide simple and efi'ective means for obviating the liability to breakage of crank-pins in the crankshafts of steam and other engines, and for facilitating and economizing renewals and repairs of said shafts and their bearings, speoially' in the case of marine engines, either at sea or in port, to which ends my improvements consist in a sectional or transverselydivided crank-pin, each section of which is secured to an arm or crank of a crankshaft; also, in the combination of ,a crank-shaft, a

' pair of crank-arms thereon, and a sectional or transverseiydivided crank-pin; also,'in the combination of a crankshaft, a pair of crankarms thereon, and a transversely divided cranlopin having a collar upon each of itssections, between the bearing-surface thereof and the eye of the crank; also, in the combination of a crankshaft, a pair of crank-arms thereon, a transversely-divided crank-pin, and a crankpin box or brass having a bearing-surface for a stub-end at and adjacent to each of its ends and an intermediate collar or flange; also, in the combination of a crankshaft, a pair of crank-arms thereon, and a crank-pin divided transversely into two independent sections, each secured in the eye of one of the crankarms by a key and feather.

The improvements claimed are hereinafter more fully set forth.

In the accompanying drawings, Figure 1 is a side view, in elevation, of a crank-shaft embodying my invention; Fig. 2, a similar view, showing a pair of crank-arms with the crankpin box in position, and illustrating the method of securing the crank-pin sections by keys and feathers; Fig. 3, a transverse section through the crank-shaft, with a crank-arm in elevation; Fig. 4, a side view, in elevation, of a pair of crank-arms with a divided crank-pin and its box, showing a different construction of the connecting-rod end; Fig. 5, a View in (No model.)

perspective of one section of adivided crankpin detached; Fig. 6, an end view of a crankpin box, and Fig. 7 a view in perspective of the same.

As heretofore constructed, so far as my.-

knowledge and information extends, the crankpins of pairs of cranks have been formed in a single piece, which is ordinarily secured in the eyes of the cranks by being shrunk in. Under such construction, crank-pins, especially those of steam-vessels, in which two or more pairs of cranks are usually employed, are liable to breakage under the undue and excessive strains to which they are at times subjected, and the difficulty, loss of time, and expense which are involved in drilling out a broken pin and shrinking in a new one are familiar to all marine engineers of extended experience. Pending the completion of such repairs, which are additionally difiicult if required to be made in bad weather or in a heavy sea, the engines are almost invariably completely disabled, and in many cases loss of life and property has been the result of the vessel being thus rendered to a great extent, if not entirely, helpless.

To obviate the diificulties and disadvantages attendant on the use of the ordinary crankpin, my invention presents the features of, first, reducing, as far as may be, the liability to breakage; second, affording the capacity of ready andspeedy renewal in, the event of breakage; third, admitting of any desired section of a crank-shaft being conveniently and quickly raised whenever desired to afford ac- I crank-pin, and a stock or body of proper diameter to fit within the eye of a crankarm, A at and adjacent to its opposite end. In order to-stiffeu the crank-pin sections, a collar, a",

in the crank-shaft of a double engine, having which may either butt against the face of the crank A or enter a recesstherein, is by prefence formed upon each section. of the pin, between its bearing-surface and its body, and the outer end of its bearing-surface is vchamfered or turned upon an incline or curve at its periphery, so $131131] when the two sections are brought into line a small circumferential groove will be presented, the same serving to give proper clearance to the brasses, and also to re ain lubricating material supplied thereto.

My invention is shown in Fig. l as applied two pairs of cranks, A for two fore-and-aft cylinders formed on shaft-sections A A, having the usual coupling-collars, a, but is, obviously, equally adaptable to the shaft of an engine having only asingle pair of cranks, as

in a single cylinder or a tandem compound eng ine.

My improved crank-pins may, if desired, be secured to the crank-arms by being shrunk in in the ordinary manner; but, for greater facility of insertion and removal, I prefer to effect such connection in the manner shown in Figs. 2 to 5, inclusive. In such case the eyes of the cranks are bored out with a very slight .taper, and the body of the pin correspondingly turned, so as to insure a good, snug, and moderately hard driving fit entirely through. A feather, a, formed upon the body of the pin, at or adjacent to the face of the crank-arm next the bearing-surface, fits into a corresponding recess in the arm, serving to resist turning or twisting strain upon the pin; and to further secure the pin a key, a is passed through a transverse slot, to, in the body of the pin, said key fitting at its ends in keyways or recesses a in the face of the crank-eye. The key a should be carefully and snugly fitted, and should have a very slight draft tov keep it safely in place. It may further have an adjustable stopper or keeper, secured by a tap-bolt and janrnut in the usual manner.

The crank-pin box or brass B is divided longitudinally into two halves or sections, as usual, and each of said sections may either be in a single piece, as in Fig. 4, or be divided transversely into two sections, each fitting the bearing-surface of one section of the pin, as in Fig. 2. In either case, to afford additional strength to the brass, I by preference form a collar or flange, b, upon each of its halves, said collar extending around the periphery of the brass, exterior to the plane of contact of.

the butting ends of the crank-pin sections. Said collar may be accommodated either by forking the end of the connecting-rod O,.as inv Fig. 4, or by dividing the connecting rod longitudinally into two portions, as in Fig. 2, each of said portions being fitted with a separate stub-end to embrace the brasses of the adjacent crank-pin section, and being coupled at its opposite end to the cross-head. In such case a slight degree of circumferential movement will be permitted between the two crank-pin sections, which will tend to relieve the boX from strains induced by variations in the alignment of the crank-shaft sections to which the arms are respectively attached.

I claim as my invention and desire to secure I by Letters Patent 1. A sectional or transversely divided crank-pin, each section of which is secured to one of a pair of crank-arms on a crankshaft, substantially as set forth.

2. The combination of a crank-shaft, a pair of crank-arms thereon, and asectional or transversely-divided crankpin, substantially as set forth.

8. The combination of a crank-shaft, a pair of crank arms thereon, and a sectional or transversely-divided crank-pin having a collar upon each of its sections,between the bearing-surface thereof and the eye of the crank, substantially as set forth.

4. The combination of a crankshaft, a pair a 

